FR2567508A1 - METHOD AND DEVICE FOR BONDING GLASS PLATES IN HORIZONTAL POSITION - Google Patents

Abstract

THE INVENTION RELATES TO THE BENDING OF GLASS PLATES IN A HORIZONTAL OR APPROXIMATELY HORIZONTAL POSITION. IT OFFERS, IN AN INSTALLATION INCLUDING AT LEAST ONE GLASS REHEATING OVEN, A BOMBING STATION, A HORIZONTAL CONVEYOR FORWARDING THE GLASS PLATES THROUGH THE OVEN AND THE BOMBING STATION, A CURVED SURFACE LAYING ABOVE THE HORIZONTAL CONVEYOR THE BOMBING STATION, A BLOWER CAPABLE OF DELIVERING A CURRENT OF HOT GAS, BOMBING THE GLASS PLATES BY APPLYING THEM USING THE CURRENT OF HOT GAS AGAINST THE CURVED SURFACE TO WHICH THE DESIRED CONFIGURATION IS GIVEN, THEN REFITTING THEM GENTLY ON A CARRIER FRAME WHERE THEY CONTINUE TO BE SUPPORTED, IN PART ONLY, BY THE CURRENT OF HOT GAS. THE INVENTION ALLOWS THE BOMBING OF GLASS SHEETS, BY THE UNIT OR IN ASSOCIATED FOR EXAMPLE IN PAIRS.

Description

METHOD AND DEVICE FOR BOMBING GLASS PLATES

IN HORIZONTAL POSITION

  The present invention relates to the bending of

  thermoplastics, in particular glass moving on a conveyor in approximately horizontal position, by lifting said plates from the conveyor using gaseous currents and

  application against a form of bending disposed above.

  It is known from the European patent document EP. O 005 306 to bend a glass plate by lifting it up to apply it against

  a carrier surface using a plurality of inde- pendent hot air jets.

  pendants, directed to the underside of the glass plate,

  by means of nozzle-shaped orifices formed in the upper wall of a box filled with compressed air, and then by dropping said plate from this bearing surface on a bending mold. In falling the plate then bombs by the sole effect of its own weight; possibly a pressing between the upper bearing surface and the

mold can also be performed.

  The bearing surface is also pierced with orifices through

  of which the glass plate is sucked at the same time as it is

  raised by the jets of air exerted on its lower face.

  The bending mold may be constituted by an annular frame

  re still called skeleton intended to bear on the marginal part to

  the periphery of the glass plate to be bombarded.

  In this known technique, the bending skeleton exerts a mechanical action on the periphery of the glass plate, which for bending, is brought to a high temperature so as to be deformable. In the most favorable case, this action results only from the own weight of the glass plate, but on the other hand, when the glass plate is ejected forcefully towards the skeleton or

  when pressed between the bearing surface and the annular skeleton

  the mechanical action is much more important. This mechanical action on the periphery of the glass plate is harmful; she is

  characterized by defects in the appearance of the surface of the glass and

  which may impair optical properties.

  Such defects in appearance or geometry in the marginal area

  glass plates, are particularly troublesome when it comes to automotive glazing, for which on the one hand the optical quality is essential for safety reasons and for

  which, on the other hand, because of modern laying techniques which

  said glazings directly in contact with the bodywork

  mobile, without interposition of a lining and usually by simple gluing, the entire surface of the glazing, up to its very edge is visible from the outside, thus making intolerable a defect

  of appearance even in the peripheral marginal zone.

  In addition, when the glass plate is placed or ejected on the annular skeleton, it can not prevent uncontrolled and unwanted deformation under the effect of gravity alone, central zones of

  plate, which are not supported by the skeleton.

  The object of the invention is to develop a method for bending glass plates which does not have the defects of the prior art, ie which makes it possible to produce curved glass plates having a well-controlled bending profile. , without undesirable deformation, free at the same time from defects and alterations produced by the action

mechanical bending skeleton.

  The invention also aims at an appropriate device for

the execution of the process.

  For this it proposes a method of bending glass plates in which the glass plates are applied against a bending form disposed above them, by the effect of a gas blown under said plates, after which the curved plates are deposited on a carrier device, the gas blown under the glass plates then having a reduced flow and pressure but sufficient, however, for a significant fraction of the self weight of the glass plates

  is still balanced by the dynamic pressure of the gas.

  In this method according to the invention, the carrier device

  férre no longer serves as a bending form as in the prior art, but only conveying means of convex plates, to convey them to the next workstation, in principle post-boring

or quenching.

  The bending of a glass plate to its definite configuration

  it is done exclusively by the pressure of the gas that applies the said

  plate of glass, on the whole of its surface, against the form of

  the geometry and profile correspond exactly

  those of the desired domed plate.

  Consequently, during bending, no tool can exert any mechanical pressure on the glass plate. Even when the curved glass plate is rested on the carrier device, it does not exert any harmful action on the glass, since the glass

  partly supported by the gas and that the effort exerted on the

  positive carrier is no longer sufficient to mark or deform

in any way.

  Even at the time of installation, the glass plate is slowly and gently deposited on the carrier and after installation

  it is a fraction of the weight of the important glass of the order of 80% in

  viron which is balanced by the gas flow.

  Therefore, it can not appear uncontrolled and undesirable overbending in the parts of the glass located between the support regions on the carrier device because of the significant support of the

weight of the glass by the gas.

  Due to this greatly reduced effect of the self weight of the glass, it is even possible to use as carrier device, not a carrier frame adapted to the profile of the glass plate, but instead, only a simpler carrier device. , consisting for example of three bearing lugs, likely to be suitable for

  glass plates of profiles and various configurations.

  Furthermore, according to the invention, the bending is carried out exclusively by the gas stream, which is heated, the temperature adjustment is not a parameter as essential as

  in the mechanical bending processes of the prior art. This is

  a particularly important advantage for the manufacture of

  safety treads which are hardened after bending, by quenching. Not only can the method according to the invention be used for the bending of glass plates taken individually, but it is also particularly suitable for the simultaneous bending of several glass plates arranged one above the other, which are for example then assembled with spacers to form a composite glazing. In contrast to previous methods

  for the simultaneous bending of several glass plates

  placed one above the other, the method according to the invention allows for the first time to avoid undesirable arrows, even when bending pairs of glass plates. In addition, we can

  this way bomber even couples of glass plates of configura-

  complications that could not be achieved with

ceded classics.

  In this process according to the invention, the dynamic pressure of the hot gas applied under the glass plates alternately changes from a high value of the order of 100 to 400 mm of water column (EC) to a lower value. approximately 5 to 30 mm (EC), these intervals being essentially a function of the thickness of the plates

of glass, and their number.

  Advantageously, the stream of hot gas applied under the glass plates is such that it has a uniform flow field,

  without a local pressure peak, and also that it does not possess

  no static pressure components that would lead to

  pressure gradients below the glass.

  Possibly, for example in the case of large arrows

  For strongly domed glazings, it is also possible to create a gas stream with a non-uniform flow field, which is

  to say with an essentially dynamic pressure profile that

  below marginal areas to bend strongly, presents a value

higher.

  Advantageously, before the bending, at the beginning of the bom-

  bage and even in the last section of the reheat furnace it can

  be planned to direct a stream of hot carrier gas towards the inside face.

  glass plates, a current which balances a fraction of the weight of the glass plates. Thus, it is possible to avoid possible deformations that could appear during the transport of the glass plates on the conveyor rollers. This accessory measure contributes

  also to obtain curved glass plates of good quality.

  The invention will now be described in more detail in reference

  FIG. 1 is a schematic diagram of the bending process, FIG. 2 is a device for bending a glass plate. FIG.

  according to the process of the invention, and then to the quenching of the

  said glass plate, Figure 3: a section of the device of Figure 2 along the line

III-III

  5. FIG. 4: a vertical section of the device of FIG. 2 along the line IV-IV, FIG. 5: a variant of the bending device according to the invention with two separate wind tunnels in order to create a non-uniform pressure field. under the glass,

  10. FIG. 6: A bending furnace according to the invention in longitudinal section.

  vertical, for bending in pairs of plates

of glass.

  In FIG. 1 are shown in vertical section through

  to a bending station the succession of the different stages of a bom-

according to the invention.

  As essential components, the bending station

  comprises: a horizontal roller conveyor 1, a form of

  ge 2 located in the center of the bending station and above the transpor-

  roller 1, mounted on supports to enable it to go up and down, rails 3 on either side of the bending mold 2, on

  which can move a carriage 4 equipped with a transpor-

  in the form of a carrier frame 5, a gas flow channel 6 below the roller conveyor 1 in which the gas stream

  hot air and in particular air is directed vertically upward

  the rollers of the roller conveyor 1, and a hood 10 closing the top of the bending station to capture the hot gas, connected to a tubular pipe 11 which allows the recycling of this hot gas

in channel 6.

  The production members of the hot gas stream, for example

  air volumes described in more detail below, should allow to create a homogeneous gas stream with a uniform pressure profile, without pressure peaks or with a pressure profile having a

  increased pressure only in selected locations.

  The glass plate 14, heated to the bending temperature, is sent by the drive rollers 1 driven by the motor, in the direction of the arrow F. from a heating furnace, no

  represented, even in the bending station.

  This situation, in which the glass plate does not have

  core reaches its final position in the bending station, is re-

  shown in view A of FIG. 1. At this moment of the process, the bending form 2 is in a low position, ie at a short distance only above the glass plate 14. directed from below to the glass plate 14, a stream of hot air at a temperature of about 650 ° C. and with a flow rate such that, in the case of a glass plate 4 mm thick , he

  immediately below said plate 14, a pressure of

  flow, ie a dynamic pressure, of about 10 mm of water.

  With this gas stream, the self-weight of the glass plate 14 is compensated to such an extent that the glass plate does not deform

  by taking an arrow between the conveyor rollers 1, but that

  on the other hand, the fraction of the own weight borne by the

  carriers 1 suffice to transport the plate. The flow rate and pressure of this hot air stream are adjusted according to the thickness of the

glass plate 14.

  As soon as the glass plate 14 has reached the bending station and has arrived below the bending mold 2, the flow rate and by

  Therefore the pressure of the hot gas stream is rapidly increasing.

  and up to a value sufficient to take off the glass plate 14 of the carrier rollers 1 and to apply it entirely

  against the surface of the bending form 2. This situation is

  felt on view B of Figure 1.

  As shown in the figure, a form of bom-

  bage 2 which has almost exactly the dimensions of the glazing 14.

  However, it is also possible to use bending shapes 2 having di-

slightly larger.

  As soon as the glass plate 14 is applied to the shape of

  bending 2, it is brought to extreme extreme position (view C -

  figure 1). Meanwhile the rising gas stream remains unchanged

  so that the glass plate 14 remains pressed against the shape 2

  when moving upwards. Immediately (view D - figure 1) the

  riot 4 provided with the carrying frame 5 is brought below the bending mold 2 and positioned below the glass plate 14 by sliding

on the rails 3.

  Then (view E - figure 1) while the high pressure of the gas is maintained, the bending form 2 is lowered until the glass plate 14 is at a very short distance, above

  carrier frame 5, for example a few millimeters. As soon as this

  sition is reached, the pressure of the gas stream is reduced to

  their bass, about 10 mm of water. As a result, the glass plate 14 comes to rest slowly and gently on the support frame 5 (view F). The low pressure of the gas, about 10 mm of water, is maintained;

  it forbids an unwanted arrow from the glass plate to the inside.

  5. The shape of the bending 2 is then reduced to its

extreme extreme position.

  When the bending form 2 has reached its extreme extreme position

  the trolley 4, with the glass plate 14 now curved

  carried by the carrier frame 5, is led, on the rails 3, to the outside.

  the bending station. The bending station is thus released for the

  bending process of the next glass plate 14 ', which enters

  during this time in the bending station on the conveyor rollers 1 (view G). While the glass plate 14 'reaches its position of

  bending, the bending form 2 has come down to its innermost position.

  in which its bending surface is just above

  of the glass plate 14 '. Just as in the steps of the process it

  glossy on views F and G, the gas pressure at that moment is

  maintained at its low value, in order to prevent unwanted deformations

  In particular, by taking an arrow between the conveyor rollers 1, it is found again at the origin of the bending cycle, illustrated by the view A. This bending process according to the invention is perfectly suitable for the manufacture of automotive glazing, these glazings

  after bending being possibly tempered.

  An installation for bending and tempering

  glass is described in detail in connection with FIGS. 2, 3 and 4.

  The conveyor rollers 1 constitute a trans-

  horizontal carrier within a channel-type continuous-flow reheating furnace which, however, is not shown as such,

  for reasons of better readability. The training of these rou-

  The conveyor belts 1 are made by friction coupling, with a

  flexible endless metal strip 16 driven, and stretched over

  17. On this metal band rest, free from rotation, the

  ends 18 of the conveyor rollers 1.

  In the bending station, which follows the warming oven

  fage, above the transport plane for the glass plates 14, the bending form 2 with a solid surface has the freedom of movement

  in the vertical direction and it is brought into the different po-

  With the aid of the adjustable jack 20. Transversal to the direction of transport F. in which the glass plates 14 penetrate the bending station, it is disposed in said bending station, on both sides of the form. bending 2, rails 3, on which slide two carriages 4, each carrying a carrier frame 5. These carriages each turn in turn in the bending station, they each support a glass plate 14 already curved and

  then go to one of the two quenching stations, arranged on the

  the bending station; positions in which the glass plates

  are soaked. In each of the two tempering stations, below and above

  above the carriage 4, there are installed blowing devices 22, for example constituted by ramps pierced with blowing holes 21, by means of which the glass plates 14 are subjected in the manner of

  usual at a brutal cooling.

  In the bending station, below the conveyor rollers

  1, there is arranged a flow channel 6, of rectangular section, through which the flow of hot gas with a homogeneous flow field

  is directed vertically upward. The gas stream flows

  turn of the bending form 2, it is collected by the hood in the form of

  roof 10 and reconnected in channel 6 by the tubular

11.

  The devices intended to create and regulate the gas flow are shown in detail in FIGS. 3 and 4. Since, in order to detach the glass plate 14 from the conveyor rollers 1 and to carry out the bending, it is necessary to create a current of hot gas exerting on the glass plate 14 a dynamic pressure of the order of 250 mm of water, and that uniformly over its entire surface, it is necessary to achieve, with the aid of appropriate fans, a large flow, with the indispensable pressure. The flow of gas, for example air, must in

  in addition to having, inside the enclosure, a temperature of 650 C

  viron. It is also essential that the gas flow, inside the bending chamber, be as uniform as possible, ie without disruptive turbulence which could have a deleterious effect.

on the bending process.

  Also, the devices provided for the creation of the hot gas stream must allow a rapid regulation of the pressure and the flow, so that one can quickly pass from a low pressure to

  high pressure, and vice versa.

  In order to create the necessary uniform hot air flow, it is recommended to use for example a device as described in

25675O8

  European patent document published under number O 106 758. In this

  previously described, the hot gas is sent radially by a fan into an enclosure whose upper wall closure

  has a large number of gas outlet orifices, of de-

  completed and in accordance with a provision also determined; the distance between the closure wall provided with the gas outlet orifices, and the

  the glass plate being such that the gas jets meet and

  cover to form a homogeneous flow field, at the level of the

  glass plate. In addition, the exhaust surface for the gas,

  by the edges of the glass plate and the closure wall, is at least as large, and preferably larger, than the sum of the sections of the gas outlet orifices in the closure wall.

  of the enclosure, on a surface equal to that of the glass plate.

  Transverse flow fans can also be used.

  sal, which are particularly interesting in the

  These fans not only have channels with rectangular sections, which are particularly well suited to our problem, and favorable flow conditions, but they can also be used at relatively high temperatures because the turbine bearing housings are arranged at the outside of the hot gas stream. In addition,

  with such cross-flow fans, the possibilities of regulating

  are better and congestion is reduced.

  On the embodiments of Figures 3 and 4, there is therefore provided a transverse flow fan 28 to create the hot air stream. A supply channel 29 of the fan 28, of rectangular section,

  is connected to the tubular pipe 11, resulting from the ventilation hood

  cuation 10 above the bending station. A turbine 32, with

  33, rotates in a housing 31, while its bearings 34 are outside the housing 31. The drive of the turbine 32 is effected by a motor 36. The outlet channel 37 having approximately

  near the section of the hot air flow required in the zone of

  bage, is located above the fan 28, below the bending zone and it opens into the flow channel 6, through which the

  gas flow is directed to the glass plates.

  Between the supply channel 29 and the tubular duct

  11, there is arranged a channel section 39, in which devices

  electric heating systems are installed to heat the

  air at the required temperature of about 650 ° C.

  In the flow channel 6 are movable flaps 42, which can increase or reduce the flow. Above these flaps 42 are vertical deflectors 44, which serve to

regulate the flow of gas.

  FIGS. 3 and 4 also show the conveyor rollers 1, the rails 3 on which the carriage 4 can move.

  with the carrier frame 5, as well as the bending form 2, which is

  movably in the vertical direction using the cylinder 20 or an equivalent mechanical lifting system. The jack 20 is mounted, using the spacers 46, inside the exhaust hood 10. On either side of the bending station, one can still recognize a station of

  quenching, which comprises the blowing devices 22, installed

  above and below the transport plane for glass plates

already curved.

  The blowing devices 22 are connected, by means of suitable flexible hoses 48, to caissons 49 supplied with air or gas

  quenching, preferably at room temperature.

  In FIG. 3, the last section is also shown.

  heating the glass plates before entering the bending station. In this last section, the glass plates already reach the temperature necessary for bending; there is the risk that they will deform under the effect of their own weight when

  of transport on the conveyor rollers 1. In order to exclude this risk

  that in the same reheating furnace, especially in its last

  section, a stream of hot gas, from the bottom to the top, is

  to take care of this part of the weight of the glass plates and to partially unload the conveyor rollers. As in the bending station, it is planned here too, below the

  roller conveyor 1, a flow channel in which is introduced

  a stream of hot gas, thanks to a transverse fan 53

  whose turbine 54 is driven by a motor 55. This current flows through

  homogeneously is directed towards the glass plates.

  Above the roller conveyor 1, the gas stream is collected by an exhaust hood 56, and is recycled through a tubular pipe 57. Inside the tubular pipe

  recycling the hot gas, and preferably immediately before the

  these suction of the cross-flow fan 53, there is arranged a heating block, not shown in the figure, through which the gas is heated to the necessary temperature of 650 C. The flow rate and the pressure of the gas, created by the transverse flow fan 53, are determined and adjusted according to the thickness of the plates.

  to ensure that, beneath the said glass plates, there is a pres-

  dynamic range between 5 and 30 mm of water. Thus only about 10 to 20% of the self weight of the glass plates is supported by the conveyor rollers 1. In the embodiment shown in FIG. 5, concerning an installation suitable for carrying out the process according to the invention, the transition from high flow to low flow of current

  gas and vice versa, is particularly rational and

  effective using two fans 61 and 63 transverse flow of different powers, which serve alternately to create the necessary carrier gas stream. For this purpose, on the flow channel 6 are connected the output channel 60 of one of the cross flow fans referenced for example 61, of relatively high power, and the output channel 62 of the other fan transverse flow for example 63, of relatively low power. The two output channels 60 and 62 are arranged relative to each other so that with a flap 64, one can optionally open one of the channels of

  exit 60 or 62 and then at the same time close the other 62 or 60. Ex

  the end of the tubular duct 67, respectively 68 is provided a heating block 70, respectively 72, whereby the gas stream is heated to the necessary temperature of 650 C. The gas thus heated is conveyed to the fan 61, respectively 63, via the duct 71, respectively 69. The two fans 61, 63 each turn at a speed corresponding to the flow rates and high pressures.

  and low, which are necessary for the different steps of the process.

  To apply the glass plate 14 to the bending shape 2, and keep it there, the flap 64 is put in the position that allows the supply of gas with the highest flow rate and the highest pressure, as well as its recycling. On the contrary to ensure the slow installation of the glass plate 14 after bending on the carriage 4, the flap 64 is placed in the other extreme position for the supply and recycling

  gas with the lowest flow rates and pressures.

  In Figure 5 the fan 61 is the one that is supposed to have the highest flow; accordingly to apply the glass plate 14 against the bending form 2, the flap 64 takes the position

represented in dotted lines.

  Since the process according to the invention, adapted to the

  curved glazing, whether tempered or not, is also particularly

  very well adapted to the manufacture of composite glazings comprising two or more associated glass plates, curved, tempered or not,

  we describe as an example in relation to Figure 6, a

* Tallation for simultaneous bending of a pair of glass plates.

  This bending installation comprises a furnace for heating the glass plates up to their bending temperature, a station of

  bending 77, in which the glass plates are curved at the configu-

  desired cooling station, two cooling stations 78 and 79, for

  slow cooling in stages of the glass plates and a cooling chamber 80, in which the glass plates are finally

  accelerated cooling to the usual process temperature

  later. Couplings 82 of glass plates worn on

  rings 84 arranged on mobile carts 83 are sent to

  a rate determined on rails 85, through the installation.

  Below the bending station 77, there is arranged a ventilator

  cross-flow flow 87, creating a flow of gas which is directed, by a flow channel 88, to the glass plates carried by the carriage 83. With adjusting flaps 89 or by adjusting the speed of the turbine 90 of the fan 87 by means of an ad hoc control of its motor 91, the flow velocity of the gas in the flow channel 88 can be increased to a high value, thanks to which the pair 82 of glass plates is pressed against the bending form 2. Thanks to the subsequent reduction of the flow velocity, the pair 82 of plates

  once bulging down again and slowly deposited on the

Annular transport type 84.

  The trolleys 83 are then sent to the two stations of

  78 and 79, in which there is also maintained a

  carrier gas. To create the carrier gas stream in these

  two cooling stations 78, 79, two

  transverse flow machines 94, 95, which are driven by an engine

  96. With the aid of these transverse flow fans,

  sal 94, 95, it is created in each of the two cooling stations

  a flow of gas whose rate of flow, or flow rate, is adjusted so that about 80 to 90% of the self weight of the plates

  of glass 82 is supported by the gas stream. In this way, we

  that the already curved glass plates do not take the arrow in their central zone not supported by the annular frame 84, under

the effect of their own weight.

  While the gas stream in the bending station 77 pre-

  high temperature, about 650 ° C, the temperature of the

  The gas stream in the cooling stations 78 and 79 is progressively reduced, for example to 600 C. in the enclosure 78 and 550 C. in the enclosure 79. Below this temperature of about 550.degree. C., it does not appear. no further deformation of the glass plates, so that continued support of the glass plates by the gas is no longer necessary. The glass plates can continue to be cooled

  in a conventional cooling chamber 80.

  Thanks to this installation, it is possible to

re of various dimensions.

  To reduce the consumption of hot gas, when small plates of glass are to be bombarded, it is possible to provide in the flow channel, under the transport device, one or

  several diaphragms arranged horizontally.

  The foregoing description has been made in relation to the

  treatment of glass plates, but plates of another thermoplastic material for example polycarbonate can of course be

  processed, the pressures and temperatures previously indicated

  are of course adapted according to said material.

  In the same way the transport devices have been described as being horizontal, but a slight variation with respect to this

  orientation would not alter the invention.

Claims (20)

  1. Method for bending plates of thermo-thermal material   plastic, in particular glass plates / in a horizontal or approximately horizontal position / in which the glass plates are conveyed on a horizontal conveying device through a reheating furnace, then in a bending station arranged subsequently, in which said plates are lifted from the conveyor device with the aid of a hot gas flowing upwards, are applied against a curved surface installed above the conveyor device and then are deposited on a carrier device disposed below   the curved surface against which the glass plates have been applied   devices, device through which the plates are sent to a downstream cooling station, characterized in that the curved surface has the configuration in which it is desired to bend the glass plates, thereby constituting a bending shape, in that the flow rate and the pressure of the hot gas are adjusted so that the plates   of glass are applied against the bending form to be bom-   dropped by the pressure of the gas and in that said flow rate and said pressure   are then, after bending the plates, for the removal of   on the carrying device, reduced to a value for which a significant fraction of the self weight of the glass plates is still   balanced by the dynamic pressure of the gas.   2. Method according to claim 1, characterized in that the flow rate and the pressure of the hot gas are adjusted so that the dynamic pressure acting above the plates, during the bending operation, is of the order of 100 at 400 mm of water and, apart from   the bending operation, of the order of 5 to 30 mm of water.   3. Process according to claims 1 and 2, characterized in that   that we make act, on the plates a current of hot gas with a profile   uniform flow without pressure peaks or turbulent turbulence facilitators.   4. Process according to claims 1 and 2, characterized in that   that we make act, on the plates a current of hot gas with a profile   with higher pressure on the marginal areas.   glass plates, however without any marked pressure peaks nor disruptive turbulence.   5. Process according to claims 1 to 4, characterized   that the hot gas stream is driven in a closed circuit.   6. Process according to claims 1 to 5, characterized in that   that the plates are curved with the help of a stream of hot gas whose   section corresponds roughly to the surface of the glass plates ber.   7. Method according to one of claims 1 to 6, characterized   in that, in order to create a stream of hot gas with alternately high and low flow and pressure, a fan delivering a   gaseous stream under low pressure and a fan delivering a   gaseous under high pressure, the two fans being driven simultaneously and their gas streams being alternately directed   to the glass plates thanks to a control flap.   8. Method according to one of claims 1 to 7, characterized   in that the plates are conveyed, on conveying rolls, through the reheating furnace, into the bending station and, after the bending, are deposited on an introduced carrier device   in the bending station after the bending operation itself.   Method according to one or more of claims 1 to 7,   characterized in that the plates are deposited on a device   frame-shaped annular nozzle, to be sent through the oven   in the bending station and, after bending, are   deposited again on this carrier device in the form of a frame.   Process according to one or more of claims 1 to 9,   characterized in that the plates in the last section of the reheat furnace, prior to arrival in the bending station, are partially supported by a stream of hot gas directed from below upwards, in view   to avoid deformations caused by their own weight.   11. Installation intended for the implementation of the process according to   the preceding claims, having a bending station in which   the baffle plates are routed on a ho-   rizontal, a curved surface installed above the trans-   carrier and means comprising at least one fan arranged below the carrier device for delivering a stream of gas   characterized in that the curved surface has the configuration   to bend the glass plates according to the desired profile and in this   the fan (28) is a cross flow fan.   -35 12. Device according to claim 11, characterized in that, above the bending station, there is provided for the gas stream, an exhaust hood (10) which is connected by a tubular duct (11) with the duct. supply (29) of the flow fan   transverse (28), in order to constitute a closed circuit system.   13. Device according to one of claims 11 or 12, characterized   in that to create an alternating pressure gas stream-   two high-flow fans are arranged side by side, one delivering a high-pressure stream, the other a low-pressure stream, the flow channels of each fan opening into a flow channel. common and a control pane   alternately connecting one or the other of the channels   flow with the common channel.   Device according to one or more of claims 11 to   13, characterized in that the flow rate and the pressure of the gas stream de-   delivered by a cross flow fan are adjustable by adjustment   the speed of the drive motor of said fan.   15. Device according to one of claims 11 to 14, characterized   in that heating means are provided on the system of fan ducts.   16. Device according to one of claims 11 to 15, characterized   characterized in that baffles are provided in the flow channel   below the conveyor device.   17. Device according to one of claims 11 to 16, characterized   characterized in that horizontally arranged diaphragms are provided in the flow channel.   Device according to one or more of claims 11 to   17, characterized in that the dimensions of the bending form correspond to   substantially lay on the dimensions of the glass plates.   Device according to one or more of claims 11 to   18, characterized in that the form of   bending installed above the conveyor device.   20. Application of the process according to one or more of the claims   cations 1 to 19 for the simultaneous bending of several glass plates   arranged one above the other.